Parts assembled together with fasteners securing two or more flanges together to be sealed against fluid leakage may present a problem because it is preferred that the fastener be tightened to a specified load, i.e. 75% proof load, in a hard joint while seal performance is improved if a soft joint is provided and the seal is not over compressed. A seal between flanges that is over compressed may leak because the seal may be distorted or compression set over time. A wide variety of assemblies include a seal assembled between flanges to prevent leakage of gaseous or liquid fluids between the flanges. Examples of assemblies that include seals between flanges include—but are not limited to—battery packs, fluid filled tanks, engine oil pans, transmission cases and differential cases.
One approach to limiting the extent of compression of a seal between two or more flanges is to assemble a compression limiter between the flanges. The compression limiter is assembled between flanges and receives, or is in close proximity to, a bolt used to secure the flanges together. The compression limiter fills the space between the flanges where the seal is disposed. The bolt is threaded into a separate nut and is then fully tightened or tightened to a specified load against the compression limiter. Compression limiters add cost to an assembly corresponding to the cost of the compression limiter. In addition, added assembly steps are required to assemble the bolt, the nut, and the compression limiter to the assembled flanges. The compression limiter must be held between the flanges to bridge the seal as the bolt is threaded into the nut complicating the assembly process.
This disclosure is directed to overcoming the above problems and other problems as summarized below.